When regenerating depollution means, such as a particle filter, an oxidation catalyst that has been poisoned by sulfur, a NOx trap that needs to be desulfized, or a SOx trap, it is necessary to raise the temperature of the engine exhaust gas considerably in order to obtain regeneration that is rapid, so as to minimize the overconsumption of fuel that is associated with such regeneration.
Unfortunately, this requires a very considerable increase in the temperature of the exhaust line and consequently in the temperature of the elements integrated therein.
Some strategies also rely on using the conversion of unburned hydrocarbons coming from the combustion in the engine, by making use of catalyst-forming means for the purpose of further raising the temperature level in the exhaust line.
However, temperature levels that are too high can lead to breakage, e.g. of the turbine portion of the turbocharger.
It is therefore necessary to have good control over the temperature levels involved during regeneration.